The evening before he must supervise a large concrete pour in Birmingham, construction foreman Ivan Locke learns that Bethan, a colleague from a job in Croydon with whom he had a one-night stand seven months before, has gone into premature labour. Despite his job responsibilities and although his wife and sons are eagerly awaiting his arrival home to watch an important football match, Locke decides to drive to London to be with Bethan during childbirth. Locke never forgave his father for abandoning him as a child, and he is determined not to make the same mistake, even though he has no relationship with, nor any particular feelings for, Bethan. Over the course of the one and a half-hour drive from Birmingham to London, Locke holds a total of 36 phone calls with: his boss Gareth; his backup colleague Donal; Katrina—his wife of 15 years—to confess his infidelity; his sons, Eddie and Sean, who call him separately with updates on the match and the worrisome breakdown of their mother; St. Mary's maternity unit medical personnel, Sister Margaret then Dr. Gullu, who are working with Bethan through some troubling complications; the council head, Cassidy, and local police authority, PC Davids, required for the road closures needed to allow the 225+ concrete trucks to properly access the site; and with Bethan to reassure her during her labour. During these calls, he is fired from his job, banned from his house by his wife, and asked by his older son to please return home. He coaches his assistant Donal through preparing the pour despite some major setbacks, and has imaginary conversations with his dead father, whom he envisions as a passenger in the car; he berates his father for abandoning Locke's family, and vows he will not repeat that mistake. When he is close to the hospital, Bethan calls to share the cooing of the baby, having had a successful birth.
Almost the entire film takes place within a BMW X5, which was pulled down the M6 motorway on a low flatbed trailer for most of the shoot. Shooting took place over eight nights, with the crew only taking breaks to change the three cameras' memory cards. Ivan Locke is the only character to appear onscreen; the others are only heard on the vehicle's speakerphone, with their parts also recorded in real time as they called from a conference room that served as the multiple "locations" of the various characters.
reports that 91% of 212 surveyed critics gave the film a positive review; the average rating is 7.71/10. The critical consensus states: "A one-man show set in a confined location, Locke demands a powerful performance – and gets it from a never-more-compelling Tom Hardy." The film has a score of 81 out of 100 on Metacritic based on 37 critics, indicating "universal acclaim". Olly Richards of Empire awarded the film 4/5 stars and said: "There are films to see on huge screens, but this is one that almost cries out for a small cinema, surrounded by total blackness. It's a daring experiment brilliantly executed, with Tom Hardy giving one of the best performances of his career". In his book How to Watch a Movie, David Thomson singles out this film and says: "No film I've seen in recent years is more eloquent on where we are now, and on how alone we feel. There is little left but to watch and listen." For his performance, Hardy won the Best Actor Award from the Los Angeles Film Critics Association.
